Logging tongs and means for opening and closing same



Sept. 4, 1956 D. MOORE ,76 7 7 LOGGING TONGS AND MEANS FOR OPENING ANDCLOSING SAME.

Filed June 14, 1954 IN VEN TOR. Dam/arc! Moore United States Patent 4Claims. or. 294-118 The present invention relates to improvements in adevice for opening and closing logging tongs.

In present day logging operations, the cut timber is oftenlifted andcarried by tongs suspended by a cable from a crane or other liftingdevice. The tongs have inwardly directed spikes thereon which bite intothe logs and secure them so that they may be lifted and carried. Thedifficulty encountered in the use of such devices is that the tongs donot open and release the logs automatically. When a log is lifted with apair of tongs the spikes are imbedded in the wood firmly enough thatthey remain stuck until jarred loose. The present practice is 1 to havea man at the releasing point toperform the task of jerking the tongsfree of the logs, or to allow the logs to fall the last foot or two tothe releasing point and jar the spikes loose by the impact. Both ofthese methods are impractical since they involve either additional man--power or possible damage to the loading surface where- Q on the logsfall. This is particularly true where logs are loaded on trucks ordocks.

It is the principal purpose of my invention to provide a pair of tongswhich may be opened and closed bythe. operator of the crane or jammerwithout the aid of another man and without the necessity of allowing thelogs to fall to the loading surface.

My invention comprises a pair of tongelements pivotal near the upperends and having upper arm portions extending beyond the pivot. Each ofthe upper arms has a clevis attached thereto intermediate the pivot andthe free end. A supporting cable is attached to the clevises. Links areattached to the free ends of the arm portions and extend upwardly. Aguide bar connects the upper ends of the links. The supporting cableextends upwardly through the guide bar to the boom; of the crane orjammer. A weight or hammer is slidably mounted on the supporting cableabove the guide bar and is adapted to be dropped on the guide bar toopen the tongs.

The nature and advantages of my invention will appear more fully fromthe following description and the accompanying drawings wherein apreferred form of the invention is shown. The drawings and descriptionare illustrative only and are not intended to limit the invention exceptinsofar as it is limited by the claims.

In the drawings:

Figure 1 is a front view of a pair of tongs embodying my invention inposition to carry a log;

Figure 2 is a view similar to Figure 1 except showing the tongs open;

Figure 3 is a view of a pair of tongs embodying my invention in closedposition, and illustrating the means by which the tongs are held fromclosing too far;

Figure 4 is an enlarged partial side view of the device; and

Figure 5 is an enlarged plan View of the device looking in the directionof the arrows 5--5 of Figure 1.

Referring now tothe drawings, my invention is shown in coordination witha pair of logging tong elements 10 and 11. The tong elements 10 and 11are pivoted at 12 Patented Sept. 4, 1956 and have inwardly directedspikes 13 and 14 at their lower ends. The tong elements 10 and 11 haveupper arms 15 and 16 which extend upward beyond the pivot 12 for asubstantial distance. Each arm 15 or 16 has a clevis member 17 pivotedthereto intermediate its ends. The clevis members 17 pass through a loop18 in a supporting cable 19 to support the tongs 10 and 11. The cable 19extends upwardly to a sheave mounted on a crane boom and then down to apower winch. With this construction, the weight of the tong elements 10and 11 causes them to grip objects placed between their jawsautomatically. When the tongs are placed around a log such as is shownin Figure 1, their weight causes them to close about the log, and whenthe cable 19 is drawn taut, the weight of the log itself causes thespikes 13 and 14 to' bite into the wood and secure the log for movement.

When it is desired to release the log, the cable is allowed to slacken,thus releasing the tension on the tong elements 10 and 11. However, thespikes 13 and 14 remain imbedded in the wood, so that when the cable isdrawn up to remove the tongs, the log will again be gripped. It isnecessary, therefore, to include some means by which the tong elements10 and 11 may be spread to withdraw the spikes 13 and 14 from the wood.This frequently is done'by raising the log from its resting place withthe tongs and then allowing it to fall back, thus jarring the spikesloose. However, this procedure is undesirable when the resting place forthe log is a truck bed or dock since repeated blows of the falling logsdamage the structure. In the event that the resting place of the log ison a pile of other logs, this technique could result in dislodgingthepile. In order to open the tongs without allowing the log to drop, orwithout involving additional manpower to jerk ice the spikes loose, Iprovide a mechanism on the tongs 10 and 11 which may be operated by thecrane operator to release the tongs fromthe log when desired.

To accomplish this result, I provide links 20 and 21 near the free endsof the arms 15 and 16. The links 211 and 21 are each comprised of twobars such as 20a and 20b shown in Figure 4. a The bars 20a and 2% arepositioned on either side of the arm 16 and a pivot pin 22 is providedto pivotally secure them to the arm 16. A similar pin 23 pivots thelinks 21a and 21b to the arm 15. The upper ends of the links 20 and 21are secured together by a guide bar 24 and pivot pins 25 at each end ofthe guide bar 24. The guide bar 24 has a central aperture 26 to pass thecable 19.

The members 15, 1 6, 20, 21 and 24 form a pentagon having pivotalconnections at each of its five verticles. If the guide bar 24 is forceddownward as in Figure 2, the arms 15 and 16 will be spread, thusspreading the tong elements 10 and 11. To perform this action, a Weight27 is provided above the guide bar 24. The weight 27 has a centralaperture 28 through which the cable 1h extends, so that the weight 27may slide up and down on the cable 19. A lead cable 29 is attached tothe weight 27 and extends upward beside the cable 1? to a sheave on thecrane and then to the operators platform.

When the weight 27 is drawn upon the cable 19 so that it is not restingon the guide bar 24, the Weight of the tong elements 10 and 11 causesthem to swing together. The arms 15 and 16 also swing together. If thesearms 15 and 16 are allowed to close far enough so that the distancebetween the pivot pins 22 and 23 is less than the length of the guidebar 24, the links 21) and 21 will be placed in such position thatdownward pressure on the bar 24 will fail to open the tongs. To preventthis from occurring, I provide short extensions 30 on the arms 15 and 16beyond the pivots 22 and 23. Transverse stop pins 31 are attached to theends of the extensions 30. When the arms 15 and 16 close far enough sothat the links 20 and 21 are nearly in a vertical position, the stoppins 31 strike the links 20 and 21 and hold the arms 15 and 16 fromclosing further. Figure 3 shows the device in such a position.

The operation of the device is very simple. 'The operator merely allowsthe weight 27 to rest upon the bar 24, thus holding the tongs 1.0 and 11open. When the tongs are positioned around a log, he draws the weight 27up and the tongs and 11 close on the log. When it is desired to releasethe log, the operator allows the cable 19 to slacken enough that thereis no tension on the tongs 10 and 1.1. Then he drops'the weight 27 onthe guide bar 24. This forces the spikeslS and 14 out of the log andopens the tongs to receive the next log.

It is believed that the nature and advantages of my invention appearfully from the foregoing description and the accompanying drawings.

Having thus described my invention, 1 claim:

1. A device for lifting and carryinglogs or the like comprising a pairof curved'tong elements pivotally connected near their upper ends andcrossing each other at the pivotal connection, an arm portion on eachtong element extending upwardly beyond the pivotal connection, aconnecting member attached to each arm portion intermediate the pivotalconnection and the free end, a supporting cable attached to theconnecting members, a link pivotally attached to the free end of eacharmportion and extending upwardly, a guide bar pivoted to and connectingthe upper ends of the links, the supporting cable extending through theguide bar, a'hammer member slidable on the cable above the guide bar sothat it may be dropped on the guide bar and links to spread the tongs,and means to lift said hammer member.

2. A device for lifting and carrying logs or the like comprising a pairof curved-tong elements pivotally connected near their upper ends andcrossing each other at the pivotal connection, an arm portion ,on eachtong element extending upwardly beyond ,the pivotal connection, aconnecting member attached to each arm portion intermediate the pivotalconnection and the free end, a supporting cable attached to theconnecting members, a link pivotally attached to the free end of eacharmportion and extending upwardly, a guide'bar pivoted {to and connectingthe upper ends of the links, the supporting cable extending through theguide bar, extensions on the arm portions adjacent the links,stop-members on the extensions whereby to engage the links as the upperends of the arm portions approach each other and thereby position thelinks upright, a hammer member slidable on the cable above the guide barso that it may be dropped on the guide bar and links to spread thetongs, and means to lift said hammermember.

3. A device for lifting and .carryinglogs ,or ,thelike comprising a pairof curved tong elements pivotally connected near their upper ends andcrossing each other at the pivotal connection, an arm portion on eachtong element extending upwardly beyond the pivotal connection, a clevispivotally attached to each arm portion intermediate the pivotalconnection .and the free end, a supporting cable having a loop formed inits end, said loop passing through each clevis and securing ittothecable, a pair of links positioned at the free end of each arm portion,said links beingpivotedto each side of the arm and extending upwardly, aguide 'bar positioned above the armportions and being.pivotallyconnectedat each end to the upper ends of the pairsoflinks,said guide bar having an aperture therein intermediate its ends, thesupporting cable passing through said aperture, a Weight slidable on thesupporting cable above the guide bar so that it may be dropped on theguide bar and links to spread the tongs, and means connecte'd to theweight to lift it from the guide bar.

4. A device 'for lifting and carrying logs on the like comprising a pairof curved tong elements pivotally connected near their upper ends andcrossing each other at the pivotal connection, an arm portion .on eachtong element extendingupwardlyibeyond the pivotal connection, a clevispivotally attached to each arm portion intermediate the pivotalconnection and the free end, a

supporting cable having a loop formed in its end, said loop passingthrough each clevis and securing it to the cable, apair of linkspositioned at the free end of each arm portion, said links being pivotedto each side of the arm-and extending upwardly, a guidebar;positioned.above the arm portions and being pivotally connected ateach end to the upper ends of the pairs of links, said guide ban-havingan aperture therein intermediate its ends, the supporting cable passingthrough said aperture, extensions on the arm-portionsadjacent the links,stop members attached to the ends of the extensions, said stop memberseach extendingtransversely of the pairs of links whereby-to en-gagethelinks as the upper ends of the arm portions approach each other andthereby position the links upright, a weight slidable on the supportingcable above the guide bar so that -it may be dropped on the guide barand'links to spreadthe tongs, and means connected tothe weight to liftit from the guide bar.

References :Cited in the file of this patent UNITED STATES PATENTS2,494,010 'Spann, Ian. .10, 1950 FOREIGN .PATENTS 206,391 GermanyFeb.'2, 1909

